Arthrorhaphis arctoparmeliae Kocourk. & van den Boom
Herzogia 18: 24, 2005
Description: Thallus not visible, not lichenized, the hyphae developing in the thalli of Arctoparmelia incurva, the infected parts turning blackish. Apothecia lecideine, black, (0.15-)0.25-0.35(-0.4) mm wide, for a long time globose and closed, later conical, sessile and constricted at base, round to irregular (flexuose or angular), with a prominent up to 60(-80) μm wide proper margin. Proper exciple dark olivaceous brown to almost black, 20-25 μm wide in upper part, c 10 μm wide at base; epithecium pale olivaceous green; hymenium colourless, 200-250 μm high; paraphyses 1.2-1.7 μm thick, anastomosing, inspersed with yellow oil droplets which later become crystallized; hypothecium colourless to pale aeruginose green. Asci (4-)6(-8)-spored, clavate to subcylindrical, thin walled throughout, with a small tholus or poorly developed ocular chamber, 110-135 x 14-17 μm. Ascospores 12-17-septate, hyaline, acicular, parallel in ascus, (60-)65-100(-110) x (3-)3.5-5(-5.5) μm, often slightly curved, sometimes straight or rod-shaped. Photobiont absent. Spot tests: all negative. Chemistry: an aeruginose pigment in epithecium and exciple.
Note: a recently-described, non lichenized lichenicolous fungus infecting the thalli of Arctoparmelia incurva, hitherto known only from a few localities in the Carpathians. To be looked for in the Italian Alps.